Bottle cap



- Feb. 28, 1933. A, H, WART 1,899,784

BOTTLE CAP Filed April 1, 1931 await Lam Patented Feb. 28, 1933 UNITED STATES PATENT OFFICE H.W.'ARTH, F BALTIMORE,

MABYLAN,

PANY, ING, OF BALTIMORE, MARYLAND, A OORPORATION OF NEW YORK BOTTLE GAP Application filed April 1,

This invention relates to bottle caps and more particularly to a cap consisting of ametallic'shell containing a cushion disc having what is known as a protecting facing. In its preferred form, the invention relates to that type of cap having a protecting facing in the form of a center-disc or center-spot which is of smaller diameter than the cushion disc.

In closures of this character, the cushion or compressible disc is ordinarily formed of sheet cork or of a composition of granular cork, the particles of which are united by a binder which is resistant to gas and acids.

It is desirable to protect the cushion disc from the contents of the bottle, since the cork or other material of the disc becomes discolored and imparts an undesirable flavor or taint to the contents.

The facing discs have ordinarily been fornied either of metal foil, such as aluminum or tin, or of fibrous material, such as paper.

The present invention relates to the latter type in which the facing is of paper.

An object of the invention is to provide a facing of the paper type which will afford a more efficient seal than has heretofore been obtainable with papers, particularly in the capping of liquids, which in the bottling process, are subjected to high heat and pressure, for example during pasteurizingor sterilizing steps.

vMoreover, the invention seeks to provide a paper facing which will produce an effective seal for waters having a high permeating power, such as distilled water and waters of low mineral content which are bottled cold. A

Further, the invention aims to provide a paper facing which will afford a suitable seal for volatile liquids such as alcohol.

The paper ordinarily used in this type of cap is hlghly glazed or provided with a water-finishor super-calendered finish, such as express paper or water-finish or super-calpractically 1931. Serial No. 527,012.

ASSIGNOR TO GROWN CORK & SEAL COH- endered unbleached kraft and substantially impervious to liquid.

For the purpose of rendering it still moreresistant, it has been provided with a coating of varnish which renders the material particularly suitable for bottling ginger ales and various soda waters.

But it has been found that, under conditions of heat and pressure which exist during the bottling or pasteurization of such liquids as beers and ales, or the pasteurizing of such liquids as milk, paper of this character will not conform to slight irregularities in the 4 surface of the bottle lip which it engages. The result is that during the period of pasteurization or sterilization, there is a slight leakage.

Moreover,in the sealing of carbonated waters, there is required a more elfective' seal than is necessary in the bottling of syruped beverages, the syrup content of which tends to prevent any seepage of the liquid, or of the gas content if it is carbonated.

I have found that for such types of liquids and for volatile liquids, such as alcohol, the

sealing action of the cap may be made more i e ective if a slightly porous paper or one not entlrely impervious to liquid is employed for the facing or center spot.

I prefer a bleached paper, since it is found that the bleached papers are inherently porous and have characteristics which render them very much preferable to unbleached papers; For example, bleached kraft paper, which may be machine glazed and even sized to an appreciable extent provided its relative porosity is retained, is particularly suitable.

kraft paper, rendering it particularly suitable for the purpose described, as compared for example to unbleached kraft, is that it is able taste to the capped liquid or beverage. It 1s particularly important, since the paper becomes saturated to some extent. with the liqn important characteristic vof bleached tasteless and imparts no objectionuid, that it have no ingredients which impartan objectionable or foreign taste to the liquid. I have found that this is particularly true with respect to bleached kraft pa er. I have also used with satisfactory e ect papers made from rope and jute fibres. Such papers when coated with varnish to provide a liquid and acid resistant surface are slightly pervious, and this is true-even though a sub stantial film of varnish may be applied. In my copending application, Serial No. 360,895, filed May 5, 1929, I have referred to the use of a bleached kraft paper provided with a water-finish which virtually eliminates the porosity of the paper, and the present application refers to the use of such paper without a water-finish as typical of papers which may be used for the purposes herein described.

I have found that, under heat and pressure which exists during the pasteurization of bottled beers and ales or during the sterilizing of other liquids, such as milk-or milk beverages, a slight absorption of moisture by such paper takes place. This results in a slight swelling of thepaper stock, due to its pervious character and causes a distinct tightening of the seal which remains permanent on cooling. This improvement in the seal is possibly aided by a temporary softening of the adhesive on the under or unexposed side of the paper,

since the paper being pervious, permits the liquid to engage the adhesive.

To unite the facing to the cushion disc, I

prefer to employ a waterproof adhesive, for example, gutta percha. By gutta percha, I mean either substantially pure gutta percha or a gutta percha compound.

This permeation of the paper sufficient to swell the paper and produce a tight seal at high pressure, such as 80 pounds at 143 F.,and also at the higher pressures and temperatures used in sterilizing beverages.

Moreover, a facing of this character has been found to be particularly efi'ective with -waters which have a permeating power it hasbeen found that this facing due to the greater than that of solutions of fruit acids; for example distilled water and waters of low mineral content. The slight permeation by these liquids seems to improve the seal particularly when a liquid resistant adhesive layer of gutta percha or gutta percha compound is employed for the purpose of uniting the facing to the cushion disc. The same applies to volatile liquids such as alcohol, and

slight permeation of the paper by the liquid,

effectively prevents the escape of the vapors.

For coating the paper I prefer a varnish which is resistant to the predominant acids and salts-in the particular beverages with which the caps are to be used.

' 'For caps to be employed with beers, I prefer a varnish which is resistant to lactic acid I by heat vapors or the liquid is not extensive, but is and the salts of beers. It is possible to provide such a varnish which will also resist the salt and alkaline ingredients in mineral waters, as well as the action of fruit acids .(tartaric acid, citric acid and malic acid),

as well as vinegar and alcohol. For example, an appropriate varnish may be prepared from the following constituents:

Amberol gum 100 lbs.

China-wood oil 29 gals. Linseed oil 3 gals. Varnoline 60 gals.

For a drier, there isused 1 of manganese to'which may be added 1% of soya bean lecithin, or any other plasticizer, such as paraflin wax which will not impart a taste to the liquid. Obviously, other formulae may be employed which will include other resins and even eliminate the linseed oil.

It may be desirable, although not es'sential, to apply to the paper a priming coat of varnish. A varnish suitable for this purpose will contain a greater proportion of drying oil or varnoline and its composition may d1ffer in other respects from that of the finishing coat above referred to, the physical characteristics of the priming coat being that it will be more limpid than the finishing compoundto facilitate impregnating of the fibres and will aid in providing a glossy film when the finishing coat is applied and properly dried.

Referring to the accompanying drawing, there is shown a preferred embodiment of the invention, and in the drawing:

gigure 1 is an interior face view of a cap, an

Figure 2 is a cross sectional view. I

Referring to the drawing for a more de tailed description, there is shown, for example, a cap made in accordance with the present invention. The cap shown is of the convention-a1 crown type, and has a shell 10 rial is adhesively retained within the cap as by means of an adhesive layer 12. The exposed surface of this disc is faced, in the present instance at its center only, by a facing 13, of slightly porous or pervious paper, as'distinguished from the highly glazed and impervious paper ordinarily used. As explained, this porous paper, such as bleached kraft paper,

which is highly eflicient even though it may be machine glazed and provided with a size; to lay the fibres. The exposed surface of the paper is coated with a varnish layer 114 which may be of any suitable character, and resistant to the action of the particular beverages with. which the capis employed.

paper is preferably a bleached" The facing or spot is united to the cushion disc by means of a backing layer 15 coextensive with the disc. This backing layer is formed from a waterproof adhesive, such as sive will be disposed between the paper and.

the cushion layer in the form of gutta percha tissue and sue strip as the strip. In both heat and pressure is employed to effect union of the facing to the cushion disc. These paper is cut fromthe paper methods of applying the adhesive are described in my issued Patent No. 1,788,260, granted January 6, 1931, and consequently the method is well known in the art, and need not be here described in detail.

Of course, other adhesives than gutta percha or gutta percha compound may be employed, but I prefer these for the reason that they afford an elastic backin for the spot and ,also prevent contact wit the cork of any liquid which permeates the paper to provide the swelling action described.

This application is a continuation in part of my copending application, Serial No. 360,895, filed May 5, 1929, and of my a plication, Serial No. 414,614, filed Decem r 17, 1929.

Obviously, numerous changes may be made in the specific structure illustrate without departing from the invention, the scope of which is defined in the following claims.

I claim:

1. A bottle cap having therein a liner of cushion material provided with a facing spot member of slightly porous bleached kraft paper provided on its exposed surface with a coating of varnish, said spot member being by a backing layer of waterproof'adhesive.

2. A bottle cap having therein a liner of cushion material provided with a facin spot member of slightly porous bleached iraft paper provided on its exposed surface with a coating of varnish, said spot member being united to the cushion material by a backing layer of gutta percha.

In testimony whereof I have hereunto set my hand.

ALBIN H. WARTH.

by means of a die cut from the ti'sprocedures the application of 

